sgoodhart,

Psfred is correct that you can just replace the ball pin if the part is available. It may only be available from your MB dealer.

Worst part is getting the prechamber out. You need the special prechamber puller. If it can't be pulled, you have to take off the cylinder head and press it out.

If you can't pull the prechamber out and don't want to take off the head, try running without the ball pin and see how the engine runs. It may just give a little more black smoke. But there is always the chance that the other 2 parts of the ball pin may come loose and you will have to remove them.

P E H